Targeting deoxycytidine kinase improves symptoms in mouse models of multiple sclerosis.

Multiple sclerosis (MS) is an autoimmune disease driven by lymphocyte activation against myelin autoantigens in the central nervous system leading to demyelination and neurodegeneration. The deoxyribonucleoside salvage pathway with the rate-limiting enzyme deoxycytidine kinase (dCK) captures extracellular deoxyribonucleosides for use in intracellular deoxyribonucleotide metabolism. Previous studies have shown that deoxyribonucleoside salvage activity is enriched in lymphocytes and required for early lymphocyte development. However, specific roles for the deoxyribonucleoside salvage pathway and dCK in autoimmune diseases such as MS are unknown. Here we demonstrate that dCK activity is necessary for the development of clinical symptoms in the MOG35-55 and MOG1-125 experimental autoimmune encephalomyelitis (EAE) mouse models of MS. During EAE disease, deoxyribonucleoside salvage activity is elevated in the spleen and lymph nodes. Targeting dCK with the small molecule dCK inhibitor TRE-515 limits disease severity when treatments are started at disease induction or when symptoms first appear. EAE mice treated with TRE-515 have significantly fewer infiltrating leukocytes in the spinal cord, and TRE-515 blocks activation-induced B and T cell proliferation and MOG35-55 -specific T cell expansion without affecting innate immune cells or naïve T and B cell populations. Our results demonstrate that targeting dCK limits symptoms in EAE mice and suggest that dCK activity is required for MOG35-55 -specific lymphocyte activation-induced proliferation.

Inhibitory effects of low decibel infrasound on the cardiac fibroblasts and the involved mechanism.

INTRODUCTION: Infrasound is a mechanical vibration wave with frequency between 0.0001 and 20 Hz. It has been established that infrasound of 120 dB or stronger is dangerous to humans. However, the biological effects of low decibel infrasound are largely unknown. The purpose of this study was to investigate the effects of low decibel infrasound on the cardiac fibroblasts. MATERIALS AND METHODS: The cardiac fibroblasts were isolated and cultured from Sprague-Dawley rats. The cultured cells were assigned into the following four groups: control group, angiotensin II (Ang II) group, infrasound group, and Ang II+infrasound group. The cell proliferation and collagen synthesis rates were evaluated by means of [3H]-thymidine and [3H]-proline incorporation, respectively. The levels of TGF-ß were determined by enzyme-linked immunosorbent assay. Moreover, RNAi approaches were used for the analysis of the biological functions of miR-29a, and the phosphorylation status of Smad3 was detected using western blotting analysis. RESULTS: The results showed that low decibel infrasound significantly alleviated Ang II-induced enhancement of cell proliferation and collagen synthesis. DISCUSSION: Compared with the control, Ang II markedly decreased the expression of miR-29a levels and increased the secretion of TGF-ß and phosphorylation of Smad3, which was partly reversed by the treatment with low decibel infrasound. Importantly, knockdown of miR-29a diminished the effects of infrasound on the cardiac fibroblasts. In conclusion, low decibel infrasound inhibits Ang II-stimulated cardiac fibroblasts via miR-29a targeting TGF-ß/Smad3 signaling.

Pacritinib inhibits glucose consumption in squamous cell lung cancer cells by targeting FLT3.

Squamous cell lung cancer maintains its growth through elevated glucose consumption, but selective glucose consumption inhibitors are lacking. Here, we discovered using a high-throughput screen new compounds that block glucose consumption in three squamous cell lung cancer cell lines and identified 79 compounds that block glucose consumption in one or more of these cell lines. Based on its ability to block glucose consumption in all three cell lines, pacritinib, an inhibitor of FMS Related Receptor Tyrosine Kinase 3 (FLT3) and Janus Kinase 2 (JAK2), was further studied. Pacritinib decreased glucose consumption in squamous cell lung cancer cells in cell culture and in vivo without affecting glucose consumption in healthy tissues. Pacritinib blocked hexokinase activity, and Hexokinase 1 and 2 mRNA and protein expression. Overexpression of Hexokinase 1 blocked the ability of pacritinib to inhibit glucose consumption in squamous cell lung cancer cells. Overexpression of FLT3 but not JAK2 significantly increased glucose consumption and blocked the ability of pacritinib to inhibit glucose consumption in squamous cell lung cancer cells. Additional FLT3 inhibitors blocked glucose consumption in squamous cell lung cancer cells. Our study identifies FLT3 inhibitors as a new class of inhibitors that can block glucose consumption in squamous cell lung cancer.

Early Reduction of Glucose Consumption Is a Biomarker of Kinase Inhibitor Efficacy Which Can Be Reversed with GLUT1 Overexpression in Lung Cancer Cells.

PURPOSE: Small molecule inhibitors that target oncogenic driver kinases are an important class of therapies for non-small cell lung cancer (NSCLC) and other malignancies. However, these therapies are not without their challenges. Each inhibitor works on only a subset of patients, the pharmacokinetics of these inhibitors is variable, and these inhibitors are associated with significant side effects. Many of these inhibitors lack non-invasive biomarkers to confirm pharmacodynamic efficacy, and our understanding of how these inhibitors block cancer cell growth remains incomplete. Limited clinical studies suggest that early (< 2 weeks after start of therapy) changes in tumor glucose consumption, measured by [18F]FDG PET imaging, can predict therapeutic efficacy, but the scope of this strategy and functional relevance of this inhibition of glucose consumption remains understudied. Here we demonstrate that early inhibition of glucose consumption as can be measured clinically with [18F]FDG PET is a consistent phenotype of efficacious targeted kinase inhibitors and is necessary for the subsequent inhibition of growth across models of NSCLC. METHODS: We tested nine NSCLC cell lines (A549, H1129, H1734, H1993, H2228, H3122, H460, HCC827, and PC9 cells) and ten targeted therapies (afatinib, buparlisib, ceritinib, cabozantinib, crizotinib, dovitinib, erlotinib, ponatinib, trametinib, and vemurafenib) across concentrations ranging from 1.6 nM to 5 µM to evaluate whether these inhibitors block glucose consumption at 24-h post-drug treatment and cell growth at 72-h post-drug treatment. We overexpressed the facilitative glucose transporter SLC2A1 (GLUT1) to test the functional connection between blocked glucose consumption and cell growth after treatment with a kinase inhibitor. A subset of these inhibitors and cell lines were studied in vivo. RESULTS: Across the nine NSCLC cell lines, ten targeted therapies, and a range of inhibitor concentrations, whether a kinase inhibitor blocked glucose consumption at 24-h post-drug treatment strongly correlated with whether that inhibitor blocked cell growth at 72-h post-drug treatment in cell culture. These results were confirmed in vivo with [18F]FDG PET imaging. GLUT1 overexpression blocked the kinase inhibitors from limiting glucose consumption and cell growth. CONCLUSIONS: Our results demonstrate that the early inhibition of lung cancer glucose consumption in response to a kinase inhibitor is a strong biomarker of and is often required for the subsequent inhibition of cell growth. Early inhibition of glucose consumption may provide complementary information to other biomarkers in determining whether a drug will effectively limit tumor growth.

GLUT1 overexpression enhances glucose metabolism and promotes neonatal heart regeneration.

The mammalian heart switches its main metabolic substrate from glucose to fatty acids shortly after birth. This metabolic switch coincides with the loss of regenerative capacity in the heart. However, it is unknown whether glucose metabolism regulates heart regeneration. Here, we report that glucose metabolism is a determinant of regenerative capacity in the neonatal mammalian heart. Cardiac-specific overexpression of Glut1, the embryonic form of constitutively active glucose transporter, resulted in an increase in glucose uptake and concomitant accumulation of glycogen storage in postnatal heart. Upon cryoinjury, Glut1 transgenic hearts showed higher regenerative capacity with less fibrosis than non-transgenic control hearts. Interestingly, flow cytometry analysis revealed two distinct populations of ventricular cardiomyocytes: Tnnt2-high and Tnnt2-low cardiomyocytes, the latter of which showed significantly higher mitotic activity in response to high intracellular glucose in Glut1 transgenic hearts. Metabolic profiling shows that Glut1-transgenic hearts have a significant increase in the glucose metabolites including nucleotides upon injury. Inhibition of the nucleotide biosynthesis abrogated the regenerative advantage of high intra-cardiomyocyte glucose level, suggesting that the glucose enhances the cardiomyocyte regeneration through the supply of nucleotides. Our data suggest that the increase in glucose metabolism promotes cardiac regeneration in neonatal mouse heart.

Protective effects of vasonatrin peptide against hypobaric hypoxia-induced pulmonary hypertension in rats.

1. The aim of the present study was to investigate the in vivo effects of vasonatrin peptide (VNP) on hypoxia-induced pulmonary hypertension (HPH). 2. The HPH model was developed by subjecting rats to hypobaric hypoxia. The HPH rats were then treated with either VNP (50 microg/kg per day, i.p.) or saline (0.5 mL, i.p.) every day for 7 days. Haemodynamic indices, right ventricular hypertrophy (RVH) and remodelling of the pulmonary arteries were evaluated. In addition, plasma levels of atrial natriuretic peptide (ANP), endothelin (ET)-1 and angiotensin II (AngII) were determined, as was natriuretic peptide receptor-C (NPR-C) mRNA expression in the right ventricle. 3. Hypobaric hypoxia induced severe HPH compared with the normoxic control group. Treatment of HPH rats with VNP for 1 week significantly reduced mean pulmonary arterial pressure, pulmonary vascular resistance, RVH and muscularization of the pulmonary arteries, although pulmonary blood flow was increased in this group. In addition, significantly lower levels of plasma ET-1 and AngII and cardiac NPR-C mRNA expression were observed in VNP-treated compared with saline-treated HPH rats, whereas higher plasma concentrations of ANP were found in the former group. Acute intravenous administration of 50 microg/kg VNP significantly ameliorated pulmonary haemodynamics in HPH rats. 4. Taken together, the date indicate that VNP has certain preventative and therapeutic effects against HPH.

18F-FAC PET Visualizes Brain-Infiltrating Leukocytes in a Mouse Model of Multiple Sclerosis.

Brain-infiltrating leukocytes contribute to multiple sclerosis (MS) and autoimmune encephalomyelitis and likely play a role in traumatic brain injury, seizure, and stroke. Brain-infiltrating leukocytes are also primary targets for MS disease-modifying therapies. However, no method exists for noninvasively visualizing these cells in a living organism. 1-(2'-deoxy-2'-18F-fluoroarabinofuranosyl) cytosine (18F-FAC) is a PET radiotracer that measures deoxyribonucleoside salvage and accumulates preferentially in immune cells. We hypothesized that 18F-FAC PET could noninvasively image brain-infiltrating leukocytes. Methods: Healthy mice were imaged with 18F-FAC PET to quantify if this radiotracer crosses the blood-brain barrier (BBB). Experimental autoimmune encephalomyelitis (EAE) is a mouse disease model with brain-infiltrating leukocytes. To determine whether 18F-FAC accumulates in brain-infiltrating leukocytes, EAE mice were analyzed with 18F-FAC PET, digital autoradiography, and immunohistochemistry, and deoxyribonucleoside salvage activity in brain-infiltrating leukocytes was analyzed ex vivo. Fingolimod-treated EAE mice were imaged with 18F-FAC PET to assess if this approach can monitor the effect of an immunomodulatory drug on brain-infiltrating leukocytes. PET scans of individuals injected with 2-chloro-2'-deoxy-2'-18F-fluoro-9-ß-d-arabinofuranosyl-adenine (18F-CFA), a PET radiotracer that measures deoxyribonucleoside salvage in humans, were analyzed to evaluate whether 18F-CFA crosses the human BBB. Results:18F-FAC accumulates in the healthy mouse brain at levels similar to 18F-FAC in the blood (2.54 ± 0.2 and 3.04 ± 0.3 percentage injected dose per gram, respectively) indicating that 18F-FAC crosses the BBB. EAE mice accumulate 18F-FAC in the brain at 180% of the levels of control mice. Brain 18F-FAC accumulation localizes to periventricular regions with significant leukocyte infiltration, and deoxyribonucleoside salvage activity is present at similar levels in brain-infiltrating T and innate immune cells. These data suggest that 18F-FAC accumulates in brain-infiltrating leukocytes in this model. Fingolimod-treated EAE mice accumulate 18F-FAC in the brain at 37% lower levels than control-treated EAE mice, demonstrating that 18F-FAC PET can monitor therapeutic interventions in this mouse model. 18F-CFA accumulates in the human brain at 15% of blood levels (0.08 ± 0.01 and 0.54 ± 0.07 SUV, respectively), indicating that 18F-CFA does not cross the BBB in humans. Conclusion:18F-FAC PET can visualize brain-infiltrating leukocytes in a mouse MS model and can monitor the response of these cells to an immunomodulatory drug. Translating this strategy into humans will require exploring additional radiotracers.

A high-throughput screen identifies that CDK7 activates glucose consumption in lung cancer cells.

Elevated glucose consumption is fundamental to cancer, but selectively targeting this pathway is challenging. We develop a high-throughput assay for measuring glucose consumption and use it to screen non-small-cell lung cancer cell lines against bioactive small molecules. We identify Milciclib that blocks glucose consumption in H460 and H1975, but not in HCC827 or A549 cells, by decreasing SLC2A1 (GLUT1) mRNA and protein levels and by inhibiting glucose transport. Milciclib blocks glucose consumption by targeting cyclin-dependent kinase 7 (CDK7) similar to other CDK7 inhibitors including THZ1 and LDC4297. Enhanced PIK3CA signaling leads to CDK7 phosphorylation, which promotes RNA Polymerase II phosphorylation and transcription. Milciclib, THZ1, and LDC4297 lead to a reduction in RNA Polymerase II phosphorylation on the SLC2A1 promoter. These data indicate that our high-throughput assay can identify compounds that regulate glucose consumption and that CDK7 is a key regulator of glucose consumption in cells with an activated PI3K pathway.

[Leaf functional traits and nutrient resorption among major silviculture tree species in coastal sandy site.] / æ»¨æµ·æ²™åœ°ä¸»è¦é€ æž—æ ‘ç§å¶ç‰‡åŠŸèƒ½æ€§çŠ¶åŠå »åˆ†é‡å¸æ”¶ç‰¹å¾.

To understand the adaptative strategies of different tree species to drought and nutrient-deficient environment in coastal sandy site, leaf functional traits and nutrient resorption of four major silviculture tree species, i.e., Casuarina equisetifolia, Pinus elliottii, Acasia crassicarpa and Eucalyptus urophylla × E. grandis were analyzed. Leaf area and specific leaf area of coniferous species (C. equisetifolia and P. elliottii) were significantly lower, and leaf dry matter content and leaf thickness were significantly higher than those of broadleaved species (A. crassicarpa and E. urophy-lla × E. grandis). Nitrogen and P contents of mature leaf and leaf litter in broadleaved species were higher than those in coniferous species. Nitrogen and P contents of mature leaf were higher than those in leaf litter, but N:P was lower than that in leaf litter. Nitrogen and P resorption efficiencies were higher in coniferous species than those in broadleaved species. The P resorption efficiency in all species was significantly higher than N resorption efficiency. The N resorption efficiency of C. equisetifolia, P. elliottii, A. crassicarpa and E. urophylla × E. grandis was 64.2%, 63.1%, 47.0% and 16.8%, and the P resorption efficiency was 92.5%, 81.6%, 80.3% and 18.0%, respectively. The specific leaf area was significantly positively correlated with leaf N and P contents, but negatively correlated with leaf dry matter content, leaf thickness, and nutrient resorption efficiency. Leaf dry matter content was significantly positively correlated with leaf thickness and nutrient resorption efficiency. Therefore, C. equisetifolia and P. elliottii belonged to slow investment species with a higher nutrient resorption efficiency, while A. crassicarpa and E. urophylla × E. grandis belonged to fast investment species with lower nutrient resorption efficiency. Different tree species developed different adaptive strategies to coastal sandy environments through the interactions between leaf functional traits and nutrient resorption.

Rapid, efficient, and economical synthesis of PET tracers in a droplet microreactor: application to O-(2-[18F]fluoroethyl)-L-tyrosine ([18F]FET).

BACKGROUND: Conventional scale production of small batches of PET tracers (e.g. for preclinical imaging) is an inefficient use of resources. Using O-(2-[18F]fluoroethyl)-L-tyrosine ([18F]FET), we demonstrate that simple microvolume radiosynthesis techniques can improve the efficiency of production by consuming tiny amounts of precursor, and maintaining high molar activity of the tracers even with low starting activity. PROCEDURES: The synthesis was carried out in microvolume droplets manipulated on a disposable patterned silicon "chip" affixed to a heater. A droplet of [18F]fluoride containing TBAHCO3 was first deposited onto a chip and dried at 100 °C. Subsequently, a droplet containing 60 nmol of precursor was added to the chip and the fluorination reaction was performed at 90 °C for 5 min. Removal of protecting groups was accomplished with a droplet of HCl heated at 90 °C for 3 min. Finally, the crude product was collected in a methanol-water mixture, purified via analytical-scale radio-HPLC and formulated in saline. As a demonstration, using [18F]FET produced on the chip, we prepared aliquots with different molar activities to explore the impact on preclinical PET imaging of tumor-bearing mice. RESULTS: The microdroplet synthesis exhibited an overall decay-corrected radiochemical yield of 55 ± 7% (n = 4) after purification and formulation. When automated, the synthesis could be completed in 35 min. Starting with < 370 MBq of activity, ~ 150 MBq of [18F]FET could be produced, sufficient for multiple in vivo experiments, with high molar activities (48-119 GBq/µmol). The demonstration imaging study revealed the uptake of [18F]FET in subcutaneous tumors, but no significant differences in tumor uptake as a result of molar activity differences (ranging 0.37-48 GBq/µmol) were observed. CONCLUSIONS: A microdroplet synthesis of [18F]FET was developed demonstrating low reagent consumption, high yield, and high molar activity. The approach can be expanded to tracers other than [18F]FET, and adapted to produce higher quantities of the tracer sufficient for clinical PET imaging.

Incidence and radiological pattern of eosinophilic granuloma: a retrospective study in a Chinese tertiary hospital.

BACKGROUND: The incidence and radiological patterns of eosinophilic granuloma (EG) in China is not clear. We described the incidence, presentation, and imaging characteristics of Chinese EG patients in a tertiary hospital. METHODS: A retrospective chart review was performed from January 2004 to October 2017 at a single tertiary general hospital. Seventy-six patients were pathologically identified as EG. Besides, 60 patients with preoperative imaging diagnosis of "EG" were analyzed to reveal the radiological patterns and their diagnostic power. RESULTS: Fifty-three male and 23 female EG patients with a mean age of 18.1 ± 16.7 years (range 1-58 years) were retrospectively included. Significant differences were observed in gender (male to female = 2.3:1) and age (the highest incidence at the age of 0~5 years) for EG. EG predominantly involved the skeletal system: flat bones (31.43%) > irregular bones (24.76%) > long bones (22.86%) > other organs (20.95%). No obvious relationships between season, biochemical markers, and EG incidence were observed. The common presenting symptoms were pain followed with local mass, and most patients underwent surgical resection. Among 60 imagingly diagnosed "EG" patients from April 2009 to October 2017, only 22 were with histological confirmation. The correct diagnosis rates were 37.1% (13 out of 35), 16.7% (5 out of 30), and 22.2% (8 out of 36) for plain radiography, computed tomography (CT), and magnetic resonance imaging (MRI), respectively. CONCLUSIONS: Chinese EG has a varied presentation, age distribution, and gender difference. EG diagnosis is still based on biopsy or histopathology instead of imaging techniques.

[Treatment of thoracolumbar burst fractures with intelligent inflated reduction combined with percutaneous pedicle screw fixation].

OBJECTIVE: To evaluate the clinical outcome of intelligent inflated reduction combined with percutaneous pedicle screw fixation in treating thoracolumbar burst fractures. METHODS: The clinical data of 22 patients with thoracolumbar burst fractures of single segment treated from January 2013 to December 2015 were retrospectively analyzed. There were 12 males and 10 females, aged from 32 to 56 years old with an average of (42.4±8.6) years. Self-made intelligent pneumatic reset instrument was applied to 22 cases under anaesthesia reduction, and then percutaneous pedicle screw fixation was performed. Clinical features were observed and the clinical effects were evaluated by VAS, ODI, kyphotic angle (Cobb angle) and the injured vertebral anterior border height before and after operation. RESULTS: All the patients were followed up from 1 to 2.5 years with an average of 18 months. All fractures obtained bone healing, no complications such as loosening, displacement, breakage of pedicle screw and kyphosis were found. Preoperative, 1 week postoperative, and final follow-up, VAS scores of lumbar pain were 7.82±0.85, 3.09±0.92, 1.05±0.72;ODI scores were 84.2±11.2, 46.3±9.0, 12.2±4.3;Cobb angle were (16.3±5.4)°, (3.7±2.2)°, ( 5.5±2.6)°; the injured vertebral anterior border heights were (59.5±7.8)%, (86.9±6.0)%, (83.5±5.5)%, respectively. There was significant differences in VAS, ODI scores between any two times(P<0.05). At 1 week postoperative and final follow-up, Cobb angle, injuried vertebral anterior border height were obviously improved (P<0.05), and there was no significant difference between postoperative 1 week and final follow-up (P>0.05). CONCLUSIONS: It is safe and feasible surgical technique that intelligent inflated reduction combined with percutaneous pedicle screw fixation for thoracolumbar burst fractures. It has advantage of little trauma, reliable fixation, and less complication, etc. Therefore, it is a better choice for single-segment thoracolumbar burst fractures.

Noninvasive Imaging of Drug-Induced Liver Injury with 18F-DFA PET.

Drug-induced liver failure is a significant indication for a liver transplant, and unexpected liver toxicity is a major reason that otherwise effective therapies are removed from the market. Various methods exist for monitoring liver injury but are often inadequate to predict liver failure. New diagnostic tools are needed. Methods: We evaluate in a preclinical model whether 18F-2-deoxy-2-fluoroarabinose (18F-DFA), a PET radiotracer that measures the ribose salvage pathway, can be used to monitor acetaminophen-induced liver injury and failure. Mice treated with vehicle, 100, 300, or 500 mg/kg acetaminophen for 7 or 21 h were imaged with 18F-FDG and 18F-DFA PET. Hepatic radiotracer accumulation was correlated to survival and percentage of nonnecrotic tissue in the liver. Mice treated with acetaminophen and vehicle or N-acetylcysteine were imaged with 18F-DFA PET. 18F-DFA accumulation was evaluated in human hepatocytes engrafted into the mouse liver. Results: We show that hepatic 18F-DFA accumulation is 49%-52% lower in mice treated with high-dose acetaminophen than in mice treated with low-dose acetaminophen or vehicle. Under these same conditions, hepatic 18F-FDG accumulation was unaffected. At 21 h after acetaminophen treatment, hepatic 18F-DFA accumulation can distinguish mice that will succumb to the liver injury from those that will survive it (6.2 vs. 9.7 signal to background, respectively). Hepatic 18F-DFA accumulation in this model provides a tomographic representation of hepatocyte density in the liver, with a R2 between hepatic 18F-DFA accumulation and percentage of nonnecrotic tissue of 0.70. PET imaging with 18F-DFA can be used to distinguish effective from ineffective resolution of acetaminophen-induced liver injury with N-acetylcysteine (15.6 vs. 6.2 signal to background, respectively). Human hepatocytes, in culture or engrafted into a mouse liver, have levels of ribose salvage activity similar to those of mouse hepatocytes. Conclusion: Our findings suggest that PET imaging with 18F-DFA can be used to visualize and quantify drug-induced acute liver injury and may provide information on the progression from liver injury to hepatic failure.

18F-FAC PET Selectively Images Liver-Infiltrating CD4 and CD8 T Cells in a Mouse Model of Autoimmune Hepatitis.

Immune cell-mediated attack on the liver is a defining feature of autoimmune hepatitis and hepatic allograft rejection. Despite an assortment of diagnostic tools, invasive biopsies remain the only method for identifying immune cells in the liver. We evaluated whether PET imaging with radiotracers that quantify immune activation (18F-FDG and 18F-1-(2'-deoxy-2'-fluoro-arabinofuranosyl)cytosine [18F-FAC]) and hepatocyte biology (18F-2-deoxy-2-fluoroarabinose [18F-DFA]) can visualize and quantify liver-infiltrating immune cells and hepatocyte inflammation, respectively, in a preclinical model of autoimmune hepatitis. Methods: Mice treated with concanavalin A (ConA) to induce a model of autoimmune hepatitis or vehicle were imaged with 18F-FDG, 18F-FAC, and 18F-DFA PET. Immunohistochemistry, digital autoradiography, and ex vivo accumulation assays were used to localize areas of altered radiotracer accumulation in the liver. For comparison, mice treated with an adenovirus to induce a viral hepatitis were imaged with 18F-FDG, 18F-FAC, and 18F-DFA PET. 18F-FAC PET was performed on mice treated with ConA and vehicle or with ConA and dexamethasone. Biopsy samples of patients with autoimmune hepatitis were immunostained for deoxycytidine kinase. Results: Hepatic accumulation of 18F-FDG and 18F-FAC was 173% and 61% higher, respectively, and hepatic accumulation of 18F-DFA was 41% lower, in a mouse model of autoimmune hepatitis than in control mice. Increased hepatic 18F-FDG accumulation was localized to infiltrating leukocytes and inflamed sinusoidal endothelial cells, increased hepatic 18F-FAC accumulation was concentrated in infiltrating CD4 and CD8 cells, and decreased hepatic 18F-DFA accumulation was apparent in hepatocytes throughout the liver. In contrast, viral hepatitis increased hepatic 18F-FDG accumulation by 109% and decreased hepatic 18F-DFA accumulation by 20% but had no effect on hepatic 18F-FAC accumulation (nonsignificant 2% decrease). 18F-FAC PET provided a noninvasive biomarker of the efficacy of dexamethasone for treating the autoimmune hepatitis model. Infiltrating leukocytes in liver biopsy samples from patients with autoimmune hepatitis express high levels of deoxycytidine kinase, a rate-limiting enzyme in the accumulation of 18F-FAC. Conclusion: Our data suggest that PET can be used to noninvasively visualize activated leukocytes and inflamed hepatocytes in a mouse model of autoimmune hepatitis.

Evaluation of a safety resheathable winged steel needle for prevention of percutaneous injuries associated with intravascular-access procedures among healthcare workers.

OBJECTIVE: To compare the percutaneous injury rate associated with a standard versus a safety resheathable winged steel (butterfly) needle. DESIGN: Before-after trial of winged steel needle injuries during a 33-month period (19-month baseline, 3-month training, and 11-month study intervention), followed by a 31-month poststudy period. SETTING: A 1,190-bed acute care referral hospital with inpatient and outpatient services in New York City. PARTICIPANTS: All healthcare workers performing intravascular-access procedures with winged steel needles. INTERVENTION: Safety resheathable winged steel needle. RESULTS: The injury rate associated with winged steel needles declined from 13.41 to 6.41 per 100,000 (relative risk [RR], 0.48; 95% confidence interval [CI95], 0.31 to 0.73) following implementation of the safety device. Injuries occurring during or after disposal were reduced most substantially (RR, 0.15; CI95, 0.06 to 0.43). Safety winged steel needle injuries occurred most often before activation of the safety mechanism was appropriate (39%); 32% were due to the user choosing not to activate the device, 21% occurred during activation, and 4% were due to improper activation. Preference for the safety winged steel needle over the standard device was 63%. The safety feature was activated in 83% of the samples examined during audits of disposal containers. Following completion of the study, the safety winged steel needle injury rate (7.29 per 100,000) did not differ significantly from the winged steel needle injury rate during the study period. CONCLUSION: Implementation of a safety resheathable winged steel needle substantially reduced injuries among healthcare workers performing vascular-access procedures. The residual risk of injury associated with this device can be reduced further with increased compliance with proper activation procedures.

Effects of cholesterol on the phenotype of rabbit bile duct fibroblasts.

AIM: To investigate how cholesterol (Ch) can affect the phenotype of bile duct fibroblasts of New Zealand rabbits. METHODS: 16 rabbits were divided randomly into two groups: the control group and the experiment group. The rabbits in experiment group were fed with hypercholesterol diet for 8 weeks. Bile duct was dissociated from rabbits and prepared for transmission electron microscopy. The purified bile duct fibroblasts were cultured and divided randomly into three groups: control group, Ch middle concentration group (0.6 g/L), Ch high concentration group (1.2 g/L). After incubated for 72 h, the fibroblasts were made into specimens for transmission electron microscopy. The expression of alpha-actin in bile duct fibroblasts was measured by means of laser scanning confocal microscopy. RESULTS: With the transmission electron microscopy, the normal bile duct fibroblasts were shuttle-shaped, and there were abundant rough endoplasmic reticulums (RER), but few mitochondria or microfilaments in cytoplasm. This is the typical phenotype of fibroblasts. Bile duct fibroblasts of hypercholesterolemic rabbits were observed. by the transmission electron microscopy Rough endoplasmic reticulums were significantly reduced, with a lot of microfilament bundles or stress fibers appeared in cytoplasm, especially under plasma membrane. Dense bodies were scattered within these bundles. Macula densas and discontinuous sarcolemma were found under plasma membrane. It suggested that the bile duct fibroblasts of hypercholesterolemic rabbits presented the phenotype of smooth muscle cell. The cultured bile duct fibroblasts also had typical phenotype of fibroblasts. After stimulated by middle concentration cholesterol (0.6 g/L) for 72 h, there appeared lots of microfilaments in cytoplasm, but without dense body, macula densa and discontinuous sarcolemma. Observed with confocal microscopy, there were many regular bundles of microfilaments in fibroblasts treated with middle concentration ch (0.6 g/L) and the expression of alpha-actin was significantly increased. The average fluorescence value of middle concentration group was 1 628+/-189 (P<0.01 vs control group). Microfilaments and the expression of alpha-actin were greatly decreased in fibroblasts of high concentration group (1.2 g/L). The average fluorescence value of high concentration group was 1 427+/-153 (P<0.05 vs middle concentration group). There were a lower expression of alpha-actin and few microfilaments in bile duct fibroblasts of control group with an average fluorescence value of 1 224+/-138. CONCLUSION: Cholesterol can make bile duct fibroblasts have the phenotypic characteristics of smooth muscle cell both in vitro and in vivo and this effect is more significant in vivo. The effect is probably associated with some other factors besides cholesterol.

Effects of cholesterol on proliferation and functional protein expression in rabbit bile duct fibroblasts.

AIM: To investigate the effect of cholesterol (Ch) on the growth and functional protein expression of rabbit bile duct fibroblasts. METHODS: The cultured bile duct fibroblasts were divided randomly into two groups: the control group and the experiment group (fibroblasts were incubated respectively with 0.6 g/L Ch for 12, 24, 36 and 48 h). The growth and DNA synthesis of bile duct fibroblasts were measured by the means of (3)H-TdR incorporation. The total protein content of fibroblast was measured by BSA protein assay reagent kit, then the expression of alpha-actin was analyzed semi-quantitatively by Western blot. RESULTS: After treatment with 0.6 g/L Ch for 12, 24, 36 and 48 h, the values of (3)H-TdR incorporation of bile duct fibroblasts were respectively 3.1+/-0.39, 3.8+/-0.37, 4.6+/-0.48 and 5.2+/-0.56 mBq/cell, and the values of the corresponding control groups were 3.0+/-0.33, 3.2+/-0.39, 3.7+/-0.49 and 4.3+/-0.43 mBq/cell. After comparing the values of experiment groups and their corresponding control groups, it was found that the (3)H-TdR incorporation of bile duct fibroblasts after treatment with 0.6 g/L Ch for 24, 36 and 48 h were significantly increased (P<0.05, P<0.01, P<0.01), while the (3)H-TdR incorporation of 12-h group was not different statistically from its control group. Ch had no obvious effect on the total protein content of fibroblasts. After incubated with 0.6 g/L Ch for 12, 24, 36 and 48 h, the total protein content of each experiment group was not altered markedly compared with its corresponding control group. The values of experiment groups were 0.246+/-0.051, 0.280+/-0.049, 0.263+/-0.044 and 0.275+/-0.056 ng/cell, and those of corresponding control groups were 0.253+/-0.048, 0.270+/-0.042, 0.258+/-0.050 and 0.270+/-0.045 ng/cell. Western blot analysis revealed that the alpha-actin expression in fibroblasts affected by Ch for 12 and 24 h was not markedly changed compared with their corresponding control groups (P>0.05), the values of total gray scale of 12- and 24-h groups were 1748+/-185 and 1756+/-173, respectively. But after stimulation with Ch for 36 h, the total gray scale of fibroblasts (1923+/-204) was significantly higher than that of control group (1734+/-197). When the time of Ch treatment was lengthened to 48 h, the alpha-actin expression was markedly elevated, the total gray scale was 2 189+/-231 (P<0.01 vs control group). CONCLUSION: Moderately concentrated Ch can promote the proliferation of bile duct fibroblasts at early stage. With the prolongation of Ch treatment, the alpha-actin expression of fibroblasts was also increased, but the hypertrophy of fibroblasts was not observed.

The study between the dynamics and the X-ray anatomy and regularizing effect of gallbladder on bile duct sphincter of the dog.

AIM: To study the relationship between the radiological anatomy and the dynamics on bile duct sphincter in bile draining and regularizing effect of gallbladder. METHODS: Sixteen healthy dogs weighing 18 kg to 25 kg were divided randomly into control group and experimental group (cholecystectomy group). Cineradiography, manometry with perfusion, to effect of endogenous cholecystokinin and change of ultrastructure were employed. RESULTS: According to finding of the choledochography and manometry, in control group the intraluminal basal pressure of cephalic cyclic smooth muscle of choledochal sphincter cCS was 9.0+/-2.0 mmHg and that of middle oblique smooth muscle of choledochal sphincter (mOS) was 16.8+/-0.5 mmHg, the intraluminal basal pressure of cCS segment was obviously lower than that of mOS (P<0.01) in the interval period of bile draining, but significative difference of intraluminal basal pressure of the mOS segment was not found between the interval period of bile draining (16.8+/-0.5 mmHg) and the bile flowing period (15.9+/-0.9 mmHg) (P>0.05). The motility of cCS was mainly characterized by rhythmically concentric contraction, just as motility of cCS bile juice was pumped into the mOS segment in control group. And motility of mOS segment showed mainly diastolic and systolic activity of autonomically longitudinal peristalsis. There was spasmodic state in cCS and mOS segment and reaction to endogenous cholecystokinin was debased after cholecystectomy. The change of ultrastructure of cCS portion showed mainly that the myofilaments of cell line in derangement and mitochondria is swelling. CONCLUSION: During fasting, the cCS portion has a function as similar cardiac "pump" and it is main primary power source in bile draining, and mOS segment serves mainly as secondary power in bile draining. The existence of the intact gallbladder is one of the important factors in guaranteeing the functional coordination between the cCS and mOS of bile duct sphincter. There is dysfunction in the cCS and mOS with cholecystectomy.

[Vasorelaxing role of vasonatrin peptide in human intramammary artery in vitro].

The purpose of this study was to investigate the vasorelaxing effect of vasonatrin peptide (VNP) on human intramammary artery (HIMA).The vasorelaxing effect of VNP on HIMA was measured by means of perfusion in vitro. The effects of HS-142-1, TEA, 8-Br-cGMP and methylene blue (MB) were also observed. It was found that VNP caused a concentration-dependent relaxation in HIMA which was independent of the endothelium. 8-Br-cGMP (0.1-1000 micromol/L) also caused a concentration-dependent relaxation in HIMA. The vasorelaxing effect of VNP disappeared in the presence of HS-142-1 (20 micromol/L), an antagonist of the natriuretic peptide guanylate cyclase (GC) receptor. MB (10 micromol/L), an inhibitor of GC, not only blocked completely the relaxation of HIMA, but also enhanced the vascular contraction induced by norepinephrine. TEA (1 mmol/L), an antagonist of calcium activated potassium channels (K(Ca)), reduced but not completely blocked the vasorelaxing effect of VNP. These findings suggest that VNP can relax HIMA, which is independent of the endothelium. This effect is possibly achieved by the binding of VNP with the natriuretic peptide GC receptors in the smooth muscle cells (SMCs), leading to an increase in intracellular cGMP level. Moreover, the vasorelaxing effect of VNP is associated with K(Ca).

Predicting subtypes of thymic epithelial tumors using CT: new perspective based on a comprehensive analysis of 216 patients.

It is highly necessary to identify low versus high risk thymic epithelial tumors (TETs) before operation to guide optimal treatment strategies. Current CT diagnostic parameters could not effectively achieve this goal. We evaluated three parameters of CT scan in a cohort of 216 TETs patients. Parameters of contrast enhancement, risk of aggressiveness, and nodule with fibrous septum were evaluated in low (A, AB) versus high risk (B1, B2, B3 and thymic carcinoma) TETs. Grade of contrast enhancement showed predictive value in classifying low and high risk TETs well. A maximal contrast-enhanced range of 25.5 HU could produce 78.8% sensitivity and 68.5% specificity in determining low risk subtypes. Additionally, risk of aggressiveness parameter was demonstrated to be associated with TETs subtype (r = 0.801, P < 0.001) and may add confidence in determining low versus high risk subtypes. Furthermore, multiple nodule with fibrous septum could suggest subtype AB. Findings from this study support role of studied parameters of CT manifestations in predicting the low and high risk stages of TETs. These findings provide empirical evidence for incorporating these parameters in clinical practice for identifying TETs stage before operation, if validated in additional studies.